Hydrothermal Anhydrite in veins is usually hydrated to gypsum by groundwater in in the vicinity of-area exposures. It is often connected with the minerals halite and sulfur. Gypsum is the commonest sulfate mineral.[seventeen] Pure gypsum is white, but other substances found as impurities might give an array of colors to https://www.propanraya.com/id/produk/eco-gypsum-ee-4050